Ic card

ABSTRACT

An IC card having high reliability, which is not only in that printing can be surely conducted with respect to the reversible display layer provided on the surface of the card substrate, but also in that the IC chip is surely protected by the reinforcing sheet. An IC card which has: an IC module ( 1 ) including an IC chip ( 14 ) mounted on an insulating substrate ( 11 ), and a reinforcing sheet ( 16 ) provided over the IC chip ( 14 ) through a sealing resin ( 15 ) for sealing the IC chip ( 14 ); a card substrate ( 2 ) comprised of a resin for sealing the IC module ( 1 ); and a reversible recording layer ( 3 ) provided on at least one surface of the card substrate ( 2 ), wherein reinforcing film patterns ( 13 ), ( 13 ′) having openings ( 13   a ), ( 13   a ′) which expose the IC chip ( 14 ) mounted portion are provided on at least one of the IC chip ( 14 ) mounted surface and the non-mounted surface of the insulating substrate ( 11 ).

TECHNICAL FIELD

[0001] The present invention relates to an information recording cardhaving an information recording medium for use in an ID card(identification card), a membership card, a prepaid card, a cash card, acommuter's pass and the like, and more particularly to an informationrecording non-contact IC card having both recorded information ofelectronic data and visible information.

BACKGROUND ART

[0002] In information recording card including an ID card and a creditcard, magnetically or optically reading methods have been widely used.However, the techniques are popularized and the data in the cards iseasily altered or forged cards are spread, and there are increasingcases where people actually suffer damage from the forged cards, causingsocial problems about the privacy of personal information. For thisreason, in recent years, as a material for controlling personal data, anIC card having an IC chip incorporated into a substrate for card made ofa resin has drawn attention since it has a large data capacity and itcan contain coded data.

[0003] For exchanging information between an IC circuit and an externaldata processing apparatus, the IC card has a connection terminal forelectrically and mechanically connecting them. Therefore, the IC cardhas various problems in that the airtightness in the IC circuit must besecured, an electrostatic discharge damage is avoided, a failure of theelectrical connection between terminal electrodes is likely to occur,and the mechanisms of the reader/writer are complicated. In addition, amanual operation of inserting or putting an IC card into or on areader/writer is inevitably needed, and therefore the efficiency is lowor the operation is burdensome in some business. Therefore, there hasbeen desired the development of non-contact IC cards which need noburdensome operation and which can exchange information with a portableremote data processing apparatus.

[0004] For meeting the demand, a non-contact IC card which has anantenna utilizing electromagnetic waves and an IC chip having a memoryand a calculation function in a substrate for card has been developed.In this IC card, the IC is driven by the induced electromotive forceexcited in the antenna in the card substrate by external electromagneticwaves from a reader/writer, and no battery power source is required inthe card, and thus a card having excellent activity can be provided.According to applications, attempts are made to incorporate a thinbattery, such as paper battery, into the card to enlarge thecommunication distance or to utilize higher frequency bands, but, fromthe viewpoint of reduction in the cost and widening applications, cardsrequiring no battery are strongly desired.

[0005] For recording information onto these cards, digital recording isconducted by a recordable IC chip provided on part of the card. Fordisplay or reading of the data recorded on the card, it is necessary toread the recorded data by means of a special reading apparatus, andtherefore general users cannot read the data by themselves. For example,in membership cards in which a high premium or a point is put onmembers, information by an information note or the like is separatelyrequired if it is merely recorded onto the card. Therefore, demands ofeasy display of the recorded data are increasing.

[0006] For meeting the demands, technique has been developed in which areversible display layer (for example, reversible heat-sensitiverecording layer; hereinafter, referred to simply as “heat-sensitiverecording layer”) is provided on the surface of the card substratewherein the reversible display layer is of a polymer/low-molecule-typeand includes an organic low molecule dispersed in a resin binder, andachieves display by utilizing the opaque-transparent contrast. Thepolymer/low-molecule-type reversible display medium is constituted by asupport, e.g., a plastic sheet/colored layer/recording(polymer/low-molecule) layer/protecting layer.

[0007] Further, recently, for reducing the cost, a bare chip mountingmethod is attempted in which an IC chip is directly mounted on the cardby providing an electrode portion for connecting an antenna to the ICchip on a sheet-form insulating substrate. In this case, a face downbonding method is employed in which a protrusion called bump is formedfrom solder or gold on an electrode portion on the circuit-formedsurface of the IC chip, and connection is made to the electrode portionthrough the bump. The connection is made for filling the gap between theIC chip circuit surface and the insulating substrate with an anisotropic conductive film, a resin containing conductive particles, suchas an anisotropic conductive resin, or under filling material.

[0008] By the way, in the IC cards, for securing reliability of the ICchip operation, the IC chip is protected by a sealing resin having ahardness different from that of the card substrate. Further, foravoiding an accident that the IC chip is mechanically broken leading tolose all data, a task is to improve the IC card in mechanical strengthwith respect to bending and a point pressure caused by impact at a pointor the like. For achieving the task, a structure such that a reinforcingsheet is provided on the sealing resin to prevent the connection portionof the IC chip or the IC chip itself from being broken is considered.

[0009] A general process for producing the IC card is conducted inaccordance with, for example, the following procedure. First, a resinsheet is printed by a known printing method, such as offset printing,gravure printing, or screen printing, and protecting sheets comprised ofa thin film resin having high transparency are laminated on bothsurfaces of the printed resin sheet. Then, an IC module is disposedbetween these sheets and they are integrated by hot melting by means ofa hot press, and punched out using a die having a predetermined sizeinto a card form. Then, the card is embossed to make characters calledembossed characters, and supplied to users.

[0010] However, the above-mentioned IC card having a reinforcingmaterial poses the following problem. Specifically, when the reinforcingsheet and the sealing resin having a cure shrinkage behavior are used incombination, the reinforcing sheet deforms due to the cure shrinkage ofthe sealing resin. For this reason, when the IC module having thereinforcing sheet disposed on the IC chip sealed by the sealing resin issealed between the resin sheets (card substrate), the deformation of thereinforcing sheet cannot be satisfactorily cancelled by the cardsubstrate, so that the surface of the card substrate may become uneven.

[0011] In the card substrate having an uneven surface, when a printingoperation is conducted with respect to the heat-sensitive recordinglayer, a spacing is caused between the heat-sensitive recording layerand a thermal head, so that the heat-sensitive recording layer cannot besatisfactorily heated, leading to a problem that missing of imagerecording is likely to occur.

[0012] An object of the present invention is to provide an IC card whichcan surely protect the IC chip by a reinforcing sheet while securingsurface flatness of the card substrate, thus making it possible tosurely achieve printing with respect to the reversible display layerprovided on the surface of the card substrate.

DISCLOSURE OF THE INVENTION

[0013] For achieving the object, the present invention provides an ICcard which has: an IC module including an IC chip mounted on aninsulating substrate, and a reinforcing sheet provided over the IC chipthrough a sealing resin for sealing the IC chip; a card substratecomprised of a resin for sealing the IC module; and a reversible displaylayer provided on at least one surface of the card substrate, the ICcard being characterized in that a reinforcing film pattern having anopening which exposes the IC chip mounted portion is provided on atleast one of the IC chip mounted surface and the non-mounted surface ofthe insulating substrate.

[0014] In this IC card, providing a reinforcing film pattern having anopening which exposes the IC chip mounted portion on the insulatingsubstrate for the IC module, the insulating substrate around theperiphery of the IC chip is reinforced without increasing the height ofthe IC module. Thus, the reinforcing sheet hardly deforms due to cureshrinkage of the sealing resin for sealing the IC chip. For example, inthe card substrate comprised of hot-press laminated thermoplastic sheetshaving the IC module disposed therebetween, even when the sealing resinundergoes a temperature higher than its glass transition temperatureduring the hot-pressing, the reinforcing sheet hardly deforms.Therefore, in the card substrate sealing the IC module, flatness of thesurface including portions around the IC chip mounted portion issecured. Thus, surface flatness of the reversible display layer providedon the card substrate is secured.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a cross-sectional view showing a structure of oneexample of the IC card of the present invention.

[0016]FIG. 2 is a cross-sectional view of an important portion of an ICmodule in the present invention, showing one example of structure.

[0017]FIG. 3 is a view showing a circuit structure of the IC card.

[0018]FIG. 4 is a plan view showing a structure of the IC module.

[0019]FIG. 5 is a plan view showing an example of structure of areinforcing film pattern in the present invention.

[0020]FIG. 6 is a plan view showing another example of structure of areinforcing film pattern in the present invention.

[0021]FIG. 7 is a plan view showing still another example of structureof a reinforcing film pattern in the present invention.

[0022]FIG. 8 is a cross-sectional view of an important portion of the ICmodule in the present invention, showing another example of structure.

[0023]FIG. 9 is a cross-sectional view showing a structure of anotherexample of the IC card of the present invention.

[0024]FIG. 10 is a plan view showing a form and configuration of areinforcing film pattern in Example 1 and Example 9.

[0025]FIG. 11 is a plan view showing a form and configuration of areinforcing film pattern in Example 2 and Example 10.

[0026]FIG. 12 is a plan view showing a form and configuration of areinforcing film pattern in Example 3 and Example 11.

[0027]FIG. 13 is a plan view showing a form and configuration of areinforcing film pattern in Example 4 and Example 12.

[0028]FIG. 14 is a plan view showing a form and configuration of areinforcing film pattern in Example 5 and Example 13.

[0029]FIG. 15 is a plan view showing a form and configuration of areinforcing film pattern in Example 6 and Example 14.

[0030]FIG. 16 is a plan view showing a form and configuration of areinforcing film pattern in Example 7 and Example 15.

[0031]FIG. 17 is a plan view showing a form and configuration of areinforcing film pattern in Example 8 and Example 16.

[0032]FIG. 18 is a plan view showing a form and configuration of areinforcing film pattern in Example 17.

[0033]FIG. 19 is a plan view showing a form and configuration of areinforcing film pattern in Example 18.

[0034]FIG. 20 is a plan view showing a form and configuration of areinforcing film pattern in Example 19.

[0035]FIG. 21 is a plan view showing a form and configuration of areinforcing film pattern in Comparative Example 3 and ComparativeExample 6.

[0036]FIG. 22 is a plan view showing a form and configuration of areinforcing film pattern in Comparative Example 4 and ComparativeExample 7.

[0037]FIG. 23 is a plan view showing a form and configuration of areinforcing film pattern Comparative Example 5 and Comparative Example8.

BEST MODE FOR CARRYING OUT THE INVENTION

[0038] Hereinafter, the embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

[0039]FIG. 1 is a cross-sectional view showing one example of an IC cardof the present invention, and FIG. 2 is an enlarged cross-sectional viewof the important portion of the IC module constituting the IC card.First, the structure of an IC card according to one embodiment isdescribed with reference to these figures.

[0040] The IC card shown in these figures comprises an IC module 1, acard substrate 2 which encapsulates the IC module 1, and a reversiblerecording layer 3 provided on at least one surface of the card substrate2.

[0041] The IC module 1 is constituted with an insulating substrate 11 asa base material, and a circuit pattern 12 constituting an antenna or thelike that is formed on one primary surface of the insulating substrate11. Reinforcing film patterns 13, 13′ are provided on at least onesurface (both surfaces in the present embodiment) of the insulatingsubstrate 11. The unique structure in the present invention resides inthe reinforcing film patterns 13, 13′. An IC chip 14 is mounted on thesurface of the insulating substrate 11, on which the circuit pattern 12is formed so as to connect to the circuit pattern 12.

[0042] Further on the insulating substrate 11, a sealing resin 15 isprovided to encapsulate the IC chip 14, and a reinforcing sheet 16 isprovided over the entire top surface of the IC chip 14 through thesealing resin 15.

[0043] Next, structures of the individual members in the IC card havingthe above structure will be described in detail.

[0044] First, the insulating substrate 11 as a base material for the ICmodule 1 is comprised of a single material, e.g., polyimide; polyester,such as polyester, polyethylene terephthalate, or polyethylenenaphthalate; polyolefin, such as polypropylene; cellulose, such ascellulose triacetate or cellulose diacetate; a vinyl resin, such as anacrylonitrile-butadiene-styrene resin, an acrylonitrile-styrene resin,polystyrene, polyacrylonitrile, polymethyl acrylate, polymethylmethacrylate, polyethyl acrylate, polyethyl methacrylate, polyvinylacetate, or polyvinyl alcohol; or polycarbonate, or a mixture thereof,and any organic materials can be used as long as they have insulationproperties.

[0045] The circuit pattern 12 formed on the insulating substrate 11constitutes part of the circuit in the IC card.

[0046]FIG. 3 shows the basic circuit configuration of the IC card. Asshown in this figure, the IC card has a circuit configuration such thata rectifying diode 43, a smoothing capacitor 44, and an IC chip 14 areconnected to a resonance circuit which includes an antenna coil 41 and atuning capacitor 42. The antenna coil 41 is constituted by the circuitpattern 12 formed on the insulating substrate 11 as shown in FIG. 4, andthe tuning capacitor (42), rectifying diode (43), and smoothingcapacitor (44) may be either constituted by the circuit pattern 12 ormounted in the IC chip 14.

[0047] The circuit pattern 12 can be obtained by forming a conductivematerial layer comprised of copper, aluminum, gold, or silver on theinsulating substrate 11 by, e.g., a process of plating, vapor depositionor the like, and etching the conductive material layer to form a patterntherein. Alternatively, the circuit pattern 12 may contain a largeamount of conductive particles, particles treated with a conductivemetal, or foil-form particles, and an organic polymer/organiclow-molecular substance or its reactive substance or an inorganicadhesive material (water-glass, silicon adhesive or the like) forbinding together the particles, and may be obtained by forming apattern, in the material in accordance with a printing method (a screenprinting method, an offset printing method or the like).

[0048] Further alternatively, the circuit pattern 12 in a strip form maybe applied onto the insulating substrate 11 using an adhesive, or aconductive material foil may be applied onto the insulating substrate 11using an adhesive and etched to form the circuit pattern 12. In thiscase, as the adhesive, a polymeric organic substance/low-molecularorganic substance or a composite resin thereof may be used, and, forexample, a single material of a thermoplastic resin, e.g., a polyesterpolyurethane resin; a polyurethane resin; a polyester resin; a vinylresin, such as an acrylonitrile-butadiene-styrene resin, anacrylonitrile-styrene resin, polystyrene, polyacrylonitrile, polymethylacrylate, polymethyl methacrylate, polyethyl acrylate, polyethylmethacrylate, polyvinyl acetate, or polyvinyl alcohol; polycarbonate, ora mixture thereof can be used. Further, a conventionally known binderresin, e.g., a thermosetting resin, such as aphelion resin, an epoxyresin, or a silicone resin can be used. As the reactive organiclow-molecular agent, a compound having at least two or more isocyanategroups (—N=C═O) per molecule or a compound having an epoxy functionalgroup can be used, and a mixture of the compound having a reactivefunctional group and a compound having a functional group havingreactivity, e.g., a hydroxyl group, an amino group or the like can beused without problem.

[0049] Back to FIG. 2, the reinforcing film patterns 13, 13′ provided onboth surfaces of the insulating substrate 11 have, respectively,openings 13 a, 13 a′ which expose the IC chip 14 mounted portion andwhich are provided at positions corresponding to the periphery of the ICchip 14.

[0050] The openings 13 a, 13 a′ are individually larger than the IC chip14, and the IC chip 14 is mounted in the opening 13 a of the reinforcingfilm pattern 13 on the mounted surface. On the other hand, thereinforcing film pattern 13′ on the non-mounted surface is provided sothat the IC chip 14 is disposed inside the opening 13 a′. The peripheryof each of the openings 13 a, 13 a′ is located inside the periphery ofthe reinforcing sheet 16 provided on the IC chip 14. Therefore, theforms of the openings 13 a, 13 a′ are determined depending on the formof the IC chip 14 and the form of the reinforcing sheet 16. For example,as shown in FIG. 5, when the IC chip 14 is square and one side of the ICchip 14 is taken as “a” the openings 13 a, 13 a′ of the reinforcing filmpatterns 13, 13′ are individually in a rectangular form (e.g., square)having one side “b” of about (a+0.1) to (a+1) mm. In FIG. 5, forexplanation, the reinforcing film pattern 13′ on the non-mounted surfaceshifts, but actually the reinforcing film pattern 13′ on the non-mountedsurface is overlapped on the reinforcing film pattern 13 on the mountedsurface.

[0051] Further, the reinforcing film patterns 13, 13′ have an outerperiphery form such that at least part of the outer peripheries of thereinforcing film patterns 13, 13′ is overlapped on the outer peripheryof the reinforcing sheet 16, preferably “projects” from the outerperiphery of the reinforcing sheet 16 in a state such that the openings13 a, 13 a′, the IC chip 14, and the reinforcing sheet 16 are disposedso that their centers are aligned with one another. It is especiallypreferred that the outer peripheries of the reinforcing film patterns13, 13′ evenly “project” from the outer periphery of the reinforcingsheet 16. One example is as follows. When a square IC chip 14 having oneside “a” of 4 mm is placed in the center of the openings 13 a, 13 a′ ofthe reinforcing film patterns 13, 13′ and a circular reinforcing sheet16 having a diameter “c” of 7 mm is placed above the IC chip 14, theouter peripheries of the reinforcing film patterns 13, 13′ individuallyhave a rectangular form such that the diagonal corresponds to thediameter of the reinforcing sheet 16, more preferably a form whichcovers the rectangular form.

[0052] The reinforcing film patterns 13, 13′ having the above-describedform are comprised of a conductive material or an insulating material.

[0053] When the reinforcing film patterns 13, 13′ are comprised of aconductive material, the reinforcing film pattern 13 on the IC mountedsurface is patterned so that it is insulated from the circuit pattern12. Therefore, a bypass pattern 13 b is provided in the reinforcing filmpattern 13 at a position in which the circuit pattern 12 connected tothe IC chip 14 is formed. In this case, the reinforcing film patterns13, 13′ individually have an area possible to secure communicationcharacteristics of the antenna constituted by the circuit pattern 12.

[0054] Especially when the reinforcing film pattern 13′ on the ICnon-mounted surface has a form patterned so that the film is notoverlapped on the circuit pattern 12, communication characteristics ofthe antenna constituted by the circuit pattern 12 can be secured.Therefore, it is preferred that a bypass pattern 13 b′ is also providedin the reinforcing film pattern 13′ at a position in which the circuitpattern 12 connected to the IC chip 14 is formed.

[0055] When the reinforcing film pattern 13′ on the IC non-mountedsurface is comprised of a conductive material, the reinforcing filmpattern 13′ may have a structure such that it is divided into aplurality of portions as shown in FIG. 6. In this case, the reinforcingfilm pattern 13′ is divided per portion to be overlapped on the circuitpattern 12 on the IC mounted surface. Specifically, when the In-part andOut-part of the circuit pattern 12 connected to the IC chip 14 aredisposed on the reinforcing film pattern 13′, the reinforcing filmpattern 13′ is divided into two portions, i.e., a portion to beoverlapped on the In-part of the circuit pattern 12 and a portion to beoverlapped on the Out-part of the circuit pattern 12. Thus, even whenthe circuit pattern 12, the insulating substrate (11), and thereinforcing film pattern 13′ create a capacitor, the effect of this onthe communication characteristics can be lowered, so that goodcommunication characteristics can be obtained.

[0056] Particularly, when the reinforcing film pattern 13 on the ICmounted surface is comprised of the same material as that for thecircuit pattern 12, the reinforcing film pattern 13 and the circuitpattern 12 can be formed in the same step, so that the reinforcing filmpattern 13 which is a novel member can be provided without adding thenumber of the steps in the production process for the IC card.

[0057] On the other hand, when the reinforcing film patterns 13, 13′ arecomprised of an insulating film, with respect to the form of each of theouter peripheries of the reinforcing film patterns 13, 13′, there is noparticular limitation as long as at least part of the outer peripheriesof the reinforcing film patterns 13, 13′ is located outside the outerperiphery of the reinforcing sheet 16 as mentioned above. Therefore, thedegree of freedom for the design of the reinforcing film patterns 13,13′ can be increased. Further, in this case, a configuration of the ICmounted surface of the insulating substrate (11) may be such that thecircuit pattern 12 is provided through the reinforcing film pattern 13or the reinforcing film pattern 13 is provided over the circuit pattern12.

[0058] Further, as shown in FIG. 7, in the reinforcing film pattern 13on the IC chip 14 mounted surface, an alignment mark 13 c ispreliminarily formed for use in mounting of the IC chip 14 on theinsulating substrate 11 on which the reinforcing film pattern 13 isformed. The reinforcing film pattern 13 having the alignment mark 13 cmay be comprised of either a conductive material or an insulatingmaterial.

[0059] Further as shown in FIG. 2, the IC chip 14 includes a protrudingelectrode 14 a provided on, for example, the surface on which thecircuit is formed, and is mounted by face down bonding on the insulatingsubstrate 11 so that the protruding electrode 14 a is connected to thecircuit pattern 12 through an anisotropic conductive adhesive layer 17.The anisotropic conductive adhesive layer 17 is comprised of conductiveparticles dispersed in an adhesive resin, and can achieve conductivityonly in the thicknesswise direction.

[0060] As the adhesive resin for the anisotropic conductive adhesivelayer 17, a single material, e.g., a polyurethane resin; a polyesterpolyurethane resin; a vinyl resin, such as anacrylonitrile-butadiene-styrene resin, an acrylonitrile-styrene resin,polystyrene, polyacrylonitrile, polymethyl acrylate, polymethylmethacrylate, polyethyl acrylate, polyethyl methacrylate, polyvinylacetate, or polyvinyl alcohol; a polycarbonate resin; or an epoxy resin,or a mixture or composite thereof can be used.

[0061] As the conductive particles dispersed in the adhesive resin, gold(Au), nickel (Ni), aluminum (Al), tin (Sn), or particles obtained bysubjecting the surface of nonconductive particles, hollow particles, orfoil pieces to conductivity treatment (physical or chemical treatmentusing Au, Ni, Al, or Sn) can be used. These conductive particles may bedispersed in the adhesive resin in a state such that they have a surfacenonconductivity-treated with an organic substance or the like. Inmounting of the IC chip 14, when the IC chip 14 is pressed and heated,the nonconductivity-treated layer on the surface of thenonconductivity-treated particles breaks and the conductive surface isexposed, creating an electrical connection between the IC chip 14 andthe circuit pattern 12.

[0062] A supporting pattern 18 for filling the gap between the IC chip14 and the insulating substrate 11 may be provided under the IC chip 14.The supporting pattern 18 may be formed in the same manner as in, forexample, formation of the circuit pattern 12. It is noted that thesupporting pattern 18 is separated from the reinforcing film pattern 13on the mounted surface.

[0063] The sealing resin 15 provided for sealing the IC chip 14 isintroduced so as to encapsulate the IC chip 14 mounted on the insulatingsubstrate 11. As the sealing resin 15, an epoxy, silicone, or phenolicthermosetting resin can be used. For suppressing a stress on the IC chip14 due to volume shrinkage caused by the thermosetting reaction, asingle material of filler, hollow particles, or foil pieces, or acomplex thereof is dispersed in the sealing resin 15. The filler, hollowparticles, or foil pieces used has a size or particle size and a mixingratio appropriately adjusted for suppressing a stress caused byshrinkage.

[0064] The reinforcing sheet 16 is provided on the sealing resin 15 sothat it is bonded to the sealing resin 15. In addition, the reinforcingsheet 16 has a form such that it is surely disposed over the entire topsurface of the IC chip 14 having, for example, a rectangular form as aplane figure. For example, the reinforcing sheet 16 may have a circularform having a radius larger than the maximum continuous length (i.e.,diagonal length) of the plane figure of the IC chip 14, or asubstantially circular form obtained by eliminating a part from thiscircle.

[0065] The reinforcing sheet 16 having the above individual form may becomprised of a metal material, especially preferably a material having aVickers hardness of 200 or more. The Vickers hardness is determined inaccordance with the measurement method described in JIS-Z2244, and it isa value as measured using a Vickers hardness tester specified inJIS-B7725.

[0066] Examples of materials having a Vickers hardness of 200 or higherinclude nonferrous metal materials, such as Cu—Sn—P, Ni—Cu—Zn, andCu—Be—Ni—Co—Fe; nickel alloy materials, such as Ni—Co, Ni—Cr, andNi—Mo—Cu; nickel-iron alloy materials, such as Ni—Fe; titanium,molybdenum, and stainless steel materials, such as SUS304, SUS301,SUS316, SUS316, SUS631, ASL350, SUS430, and SUS420; and carbon steel,such as SK materials, and materials having further improved hardnessobtained by subjecting the above material to thermal treatment can beused.

[0067] It is desired that the reinforcing sheet 16 comprised of theabove material has a thickness of 25 μm or more, and for obtaining an ICcard having a thickness which falls in the range specified in ISO(760±80 μm), it is desired that the upper limit of the thickness of thereinforcing sheet 16 is 100 μm. When the thickness of the reinforcingsheet 16 falls in this range, the reinforcing sheet 16 having the formand size specified as mentioned above hardly deforms and has asatisfactory strength.

[0068] In the above explanation, the IC module 1 has a structure inwhich the reinforcing sheet 16 is solely disposed on the IC chip 14mounted surface of the insulating substrate 11, but the structure of theIC module is not limited to this and a structure may be such that areinforcing sheet 16′ is further provided on the IC chip 14 non-mountedsurface of the insulating substrate 11 through the sealing resin 15′ asshown in FIG. 8. In this IC module 1′, the reinforcing sheet 16′provided on the non-mounted surface is disposed on the back surface ofthe substrate at a position corresponding to the IC chip 14 so as to beback to back with the reinforcing sheet 16. The reinforcing sheet 16′may have the same form as the form of the reinforcing sheet 16 providedon the mounted surface, but they are not necessarily the same. Further,in this case, the forms and configurations of the reinforcing filmpatterns 13, 13′ for the reinforcing sheet 16′ are similar to those forthe reinforcing sheet 16.

[0069] The above-described card substrate 2 shown in FIG. 1 for sealingthe IC module 1 or IC module 1′ (hereinafter, both are referred to asthe IC module 1) includes, for example, two thermoplastic sheets 21, 21′hot-pressed together and the IC module 1 disposed between thethermoplastic sheets 21, 21′.

[0070] The thermoplastic resin sheets 21, 21′ are constituted using acrystalline thermoplastic resin having a crystallinity as low as 5% orless, and they may be individually comprised of either the same materialor different materials, and may be individually comprised of either asingle layer or a laminate of the same or different materials.Particularly, as the thermoplastic resin sheets 21, 21′, a singlematerial of a amorphous resin, e.g., a copolymer of terephthalic acid,cyclohexanedimethanol, and ethylene glycol; an alloy of the copolymerand polycarbonate; a copolymer of terephthalic acid, isophthalic acid,and ethylene glycol; an acrylonitrile-butadiene-styrene copolymer resin;a polystyrene resin; a polyacrylonitrile resin; a polyvinyl alcoholresin; a polymethyl acrylate resin; a polymethyl methacrylate resin; apolyvinyl acetate resin; or a polycarbonate resin, or a mixture thereofcan be used. Instead of the amorphous resin, a double-sided amorphoussheet prepared from an amorphous resin and a crystalline resin by aco-extrusion method can be used. Further, in the low crystallinitypolyester resin or another resin, an additive and a substance, such as apolymer, may be added in an amount of 50% by weight or less, preferably15% by weight or less.

[0071] When, in addition to the reversible recording layer 3, forexample, a printed layer is provided as the surface layer of the cardsubstrate 2, the printed sheet is hot-pressed, together with thethermoplastic resin sheets 21, 21′. In this case, for improving theadhesiveness between the thermoplastic resin sheets 21, 21′ and theprinted sheet by hot melting, an adhesive may be used.

[0072] As a material for the printed sheet used together with thethermoplastic resin sheets 21, 21′, a single material, e.g., polyimide;polyester, such as polyester, polyethylene terephthalate, orpolyethylene naphthalate; polyolefin, such as polypropylene; cellulose,such as cellulose triacetate or cellulose diacetate; a vinyl resin, suchas an acrylonitrile-butadiene-styrene resin, an acrylonitrile-styreneresin, polystyrene, polyacrylonitrile, polymethyl acrylate, polymethylmethacrylate, polyethyl acrylate, polyethyl methacrylate, polyvinylacetate, or polyvinyl alcohol; or polycarbonate, or a mixture thereofcan be used.

[0073] As the adhesive used together with the thermoplastic resin sheets21, 21′, a single material, e.g., a polyester resin; a polyurethaneresin; a polyester polyurethane resin; a vinyl resin, such as anacrylonitrile-butadiene-styrene resin, an acrylonitrile-styrene resin,polystyrene, polyacrylonitrile, polymethyl acrylate, polymethylmethacrylate, polyethyl acrylate, polyethyl methacrylate, polyvinylacetate, or polyvinyl alcohol; a polycarbonate resin; or an epoxy resin,or a mixture or composite thereof can be used.

[0074] Next, with respect to the reversible recording layer 3 providedon the surface of the card substrate 2, a printing operation isconducted by scanning a printing head on the reversible recording layer3, and the reversible recording layer 3 is comprised of, for example, aheat-sensitive-type reversible recording layer. In FIG. 1, an example inwhich the reversible recording layer 3 is solely provided on the ICmounted surface is shown, but the reversible recording layer 3 may beprovided on at least one surface of the card substrate 2, namely, atleast one of the IC mounted side and the IC non-mounted side.

[0075] The heat sensitive-type reversible recording layer 3 can beselected from either a polymer/low-molecule-type one or a luecocompound-type one, and may be formed by a printing method, a coatingmethod or the like so that the thickness becomes about 4 to 20 μm.

[0076] The polymer/low-molecule-type reversible recording layer 3reversibly changes from an opaque layer to a transparent layer dependingon the change in the crystal state of the organic low-molecularsubstance dispersed in the resin matrix. In the reversible recordinglayer 3 of this type, as examples of organic low-molecular substancesdispersed in the reversible recording layer 3, there can be mentionedfatty acids, fatty acid derivatives, and alicyclic organic acids, morespecifically, saturated and unsaturated fatty acids and dicarboxylicacids, and specific examples of saturated fatty acids include myristicacid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearicacid, nonadecanoic acid, arachic acid, behenic acid, lignoceric acid,cerotic acid, montanic acid, and melissic acid, and specific examples ofunsaturated fatty acids include oleic acid, elaidic acid, linoleic acid,sorbic acid, and stearolic acid. The fatty acids, fatty acidderivatives, and alicyclic organic acids are not limited to these, andone of these or a mixture of two or more of these can be used.

[0077] As the resin matrix to be used, a single material, e.g., anacrylic resin, an urethane resin, a polyester resin, a cellulose acetateresin, a nitrocellulose resin, a vinyl chloride resin, or a vinylacetate resin, or a mixture or copolymer thereof may be used. Inaddition, for controlling the range of temperatures at which thereversible recording layer 3 becomes transparent, a plasticizer for theresin, a high-boiling solvent or the like can be added in an amount of0.1 to 20% parts by weight, based on the weight of the resin matrix.Further, for improving the reversible recording layer 3 in resistance torepeated printing and erasing, a curing agent, a crosslinking agent orthe like suitable for three-dimensionally crosslinking of the resinmatrix can be added in an amount of 0.5 to 10% parts by weight, based onthe weight of the resin matrix.

[0078] On the other hand, the heat sensitive-type reversible recordinglayer 3 of a lueco compound type utilizes a reversible color reactionbetween the lueco compound and the color developing and erasing agentdispersed in the resin matrix. As a generally colorless or pale colorlueco compound used in the reversible recording layer 3,representatively, ones which are generally used in pressure sensitiverecording paper, thermal recording paper, light sensitive recordingpaper, electro-thermo sensitive recording paper, or thermal transferpaper, i.e., xanthene, spiropyran, lactone, fluoran, and sultonecompounds having a partial skeleton, such as lactone, sultone, orspiropyran are used, but there is no particular limitation.

[0079] Specific example of lueco compounds include

[0080] 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide,

[0081] 3,3-bis(p-dimethylaminophenyl)phthalide,

[0082] 3,3-bis(1,2-dimethylindole-3-yl)-6-dimethylaminophthalide,

[0083] 3-dimethylamino-6-chloro-7-methylfluoran,

[0084] 3,3-bis(9-ethylcarbazole-3-yl-5)-dimethylaminophthalide,

[0085] 3-dimethylamino-7-dibenzylaminofluoran,

[0086] 3-diethylamino-7-chlorofluoran,

[0087] 3-diethylamino-6-methyl-7-anilinofluoran,

[0088] 3-piperidino-6-methyl-7-anilinofluoran,

[0089] 3-(n-ethyl-n-nitrile)amino-6-methyl-7-anilinofluoran,

[0090] 3-dibutylamino-6-methyl-7-anilinofluoran, and

[0091] 3-(n-ethyl-n-tetrahydrofuryl)amino-6-methyl-7-anilinofluo ran,and these may be used individually or in combination.

[0092] The color developing and erasing agent is a compound whichreversibly emits protons utilizing the effect of heat energy and hasboth color developing effect and color erasing effect for the luecocompound. In other words, the color developing and erasing agent hasboth an acidic group comprised of a phenolic hydroxyl group or acarboxyl group and a basic group comprised of an amino group, andbecomes acidic or basic due to the change of heat energy to cause thelueco compound to be colored or erased. The basic group may be presenteither in the form of a functional group or in the form of part of thecompound. Examples of color developing and erasing agents having any oneof a functional group as an acidic group and a functional group as abasic group for the color developing and erasing agent includeaminobenzoic acid, o-aminobenzoic acid, 4-amino-3-methylbenzoic acid,3-amino-4-methylbenzoic acid, 2-amino-5-ethylbenzoic acid,3-amino-4-butylbenzoic acid, 4-amino-3-methoxybenzoic acid,3-amino-4-ethoxybenzoic acid, 2-amino-5-chlorobenzoic acid,4-amino-3-bromobenzoic acid, 2-amino-2-nitrobenzoic acid,4-amino-3-nitrobenzoic acid, 3-amino-4-nitrilebenzoic acid,aminosalicylic acid, diaminobenzoic acid, 2-methyl-5-aminonaphthoicacid, 3-ethyl-4-aminonaphthoic acid, nicotinic acid, isonicotinic acid,2-methylnicotinic acid, and 6-chloronicotinic acid. As a colordeveloping and erasing agent having a basic group in the form of part ofa basic compound, there can be mentioned salts or complex salts of acompound having a phenolic hydroxyl group or a carboxyl group and acompound having an amino group, and examples include salts or complexsalts of an acid, such as a hydroxybenzoic acid, a hydroxysalicylicacid, a gallic acid, or bisphenolacetic acid, and a base, such as analiphatic amine, a phenylalkylamine, or a triallylalkylamine. Specificexamples include p-hydroxybenzoic acid-alkylamine salts,p-hydroxybenzoic acid-phenylalkylamine salts, m-hydroxybenzoicacid-alkylamine salts, methyl p-hydroxybenzoate-alkylamine salts,stearyl p-hydroxybenzoate-alkylamine salts, bisphenolaceticacid-alkylamine, and octyl bisphenolacetate-alkylamine salts, and thesemay be used individually or in combination. The lueco compound and thecolor developing and erasing agent are not limited to these, and one ofthese or a mixture of two or more of these can be used.

[0093] As the resin matrix, a single resin, e.g., an acrylic resin, apolyester resin, a polyurethane resin, polyurea, a melamine resin,polycarbonate, polyamide, polyvinyl pyrrolidone, polyvinyl alcohol,polyvinyl chloride, or polyvinyl butyral, or a mixture or copolymerthereof may be used. Further, for improving the reversible recordinglayer 3 portion in resistance to repeated printing and erasing, a curingagent, a crosslinking agent or the like suitable for three-dimensionallycrosslinking of the resin matrix can be added in an amount of 0.5 to 10%parts by weight, based on the weight of the resin matrix. In addition,for improving the resistance, an ultraviolet absorber having relativelyhigh compatibility with the lueco compound can be added.

[0094] As a method for producing an IC card having the above-describedstructure, a melting lamination method by means of a hot press can beused. In production of an IC card by the melting lamination method, forexample, an IC module 1 is first disposed between two thermoplasticresin sheets 21, 21′, and then they are together disposed between mirrorplates larger than them and integrated by means of a hot-melt press.Thus, the IC module 1 is sealed into the card substrate 2. As the mirrorplate used in this instance, a nickel-chromium plated copper plate, astainless steel plate having a ground surface, or an aluminum platehaving a ground surface can be used.

[0095] Next, if desired, a printed sheet obtained by printing charactersor patterns on a resin sheet by a known printing method, such as anoffset printing method, a screen printing method, or a gravure printingmethod, is prepared. Then, the printed sheet is disposed on the cardsubstrate 2, further the reversible recording layer 3 is disposed on theprinted sheet, and the printed sheet and the reversible recording layer3 are temporarily fixed to the surface of the card substrate 2 using,for example, an ultrasonic bonding machine or the like. Then, theresultant laminate is disposed again between the mirror plates andmelted together by hot-pressing.

[0096] Then, the integrated card material is peeled off the mirrorplates, and punched out into a card form by means of single-edged ormale-female dies to produce an IC card. Further, after being punched outinto a card form, if desired, characters are embossed on the card bymeans of an embosser, and the embossed characters are colored by tippingusing a thermal transfer foil, or magnetic information is encoded onmagnetic stripes, and, if desired, a facial portrait, a barcode or thelike is transferred to the card to finish the IC card. The printing forthe surface of the card substrate 2 may be direct printing for thesurface of the thermoplastic resin sheets 21, 21′.

[0097] Alternatively, although not shown, for providing a contact ICchip, the surface of the card substrate 2 is cut to form a recess, andthen a contact IC chip is embedded in the recess using an adhesive, sothat a combination or hybrid card having both a non-contact IC (i.e., ICchip 14) and a contact IC can be produced.

[0098] The thus obtained IC card has, on the insulating substrate 11 ofthe IC module 1, the reinforcing film patterns 13, 13′ having theopenings 13 a, 13 a′ which expose the IC chip 14 mounted portion, andtherefore the insulating substrate 11 around the periphery of the ICchip 14 is reinforced without increasing the height of the IC module.Thus, the reinforcing sheet 16 hardly deforms due to cure shrinkage ofthe sealing resin 15 over the IC chip 14. In other words, in laminationof the thermoplastic resin sheets 21, 21′ by hot-pressing, even when thesealing resin 15 undergoes a temperature higher than its glasstransition temperature, the reinforcing sheet 16 hardly deforms.Therefore, in the card substrate 2 sealing the IC module 1, flatness ofthe surface including the IC chip 14 mounted portion is secured.

[0099] Thus, while protecting the IC chip 14 by the reinforcing sheet 16provided thereon, the surface flatness of the reversible recording layer3 provided on the card substrate 2 can be improved. As a result, in theIC card improved in reliability, when a printing operation is conductedon the reversible recording layer 3, a spacing between the reversiblerecording layer 3 and the printing head is reduced to enable sureprinting, thus making it possible to improve the printing properties forthe reversible recording layer 3.

[0100] The structure of the IC card of the present invention is notlimited to the structure shown in FIG. 1 in which whole of the IC chip14 and the circuit pattern 12 are provided on the same insulatingsubstrate 11, but may be, for example, a structure shown in FIG. 9 inwhich an insulating substrate 11 having mounted thereon the IC chip 14and an insulating substrate 11′ having provided thereon the circuitpattern 12 constituting an antenna or the like are individuallyprovided, and the circuit pattern 12 on the insulating substrate 11connected to the IC chip 14 is connected to the circuit pattern 12 onthe insulating substrate 11′ by wire bonding or the like. Alternatively,although not shown, a structure may be such that the insulatingsubstrate 11 is provided with a conductive material (e.g., antenna coil)extending from the substrate. Further, in the above structures, areversible display layer may be provided on the IC chip non-mountedsurface, and the same effect can be obtained.

[0101] In the above embodiment, an explanation is made on the structurein which the card substrate 2 has two thermoplastic resin sheetshot-pressed, but the IC card of the present invention is not limited toone using the card substrate 2 having the above structure, but may beapplied to one using a card substrate which has, for example, two outersheets having an adhesive resin filled therebetween, and the same effectcan be obtained. In this case, the IC module is sealed by the adhesiveresin between the outer sheets.

EXAMPLES

[0102] Next, specific Examples 1 to 19 of the present invention andComparative Examples 1 to 8 for these Examples, and the results ofevaluation therefor will be described. Here, samples for evaluation(specifically, IC cards in Examples 1 to 19 and Comparative Examples 1to 8) were produced using the forms and configurations of thereinforcing film patterns 13, 13′ shown in Table 1 below as factors,and, with respect to each evaluation sample, the printing properties forthe reversible recording layer 3, the communication characteristics, andthe static load strength were evaluated. Reinforcing film layer Portionof reinforcing film layer on IC non-mounted surface ReinforcingEvaluation On IC On IC overlapped on sheet on IC Communication ICmounted non-mounted circuit non-mounted Printing characteristicsstrength surface surface pattern surface properties (mm) (kgf) Example 1Present — — — Δ 93 8.2 Example 2 Present Present Present — ◯ 88 7.7Example 3 — Present Present — Δ 88 8.6 Example 4 Present — — — ◯ 92 8.2(Larger than reinforcing sheet size) Example 5 Present Present Present —◯ 87 8.4 (Larger (Larger than than reinforcing reinforcing sheet sheetsize) size) Example 6 — Present Present — ◯ 88 8.8 (Larger thanreinforcing sheet size) Example 7 Present Present None — ◯ 92 8.3Example 8 — Present None — Δ 93 8.7 Example 9 Present — — Present Δ 9312.3 Example Present Present Present Present ◯ 86 12.6 10 Example —Present Present Present Δ 87 12.8 11 Example Present — — Present ◯ 9312.6 12 (Larger than reinforcing sheet size) Example Present PresentPresent Present ◯ 87 12.2 13 (Larger (Larger than than reinforcingreinforcing sheet sheet size) size) Example — Present Present Present ◯88 12.7 14 (Larger than reinforcing sheet size) Example Present PresentNone Present ◯ 93 13.1 15 Example — Present None Present Δ 93 12 16Example — Present Present — ◯ 70 7.8 17 (Lager portion overlapped oncircuit pattern) Example Present Present Present Present ◯ 93 12.6 18(Larger (Larger than than reinforcing reinforcing sheet sheet size)size) Example — Present Present Present ◯ 93 12.5 19 (Larger thanreinforcing sheet size) Comparative — — — — X 93 8.3 Example 1Comparative — — — Present X 94 12.5 Example 2 Comparative Present — — —X 87 8 Example 3 (No opening) Comparative Present Present Present — X 859.1 Example 4 (No (No opening) opening) Comparative — Present Present —X 87 8.4 Example 5 (No opening) Comparative Present — — Present X 8812.9 Example 6 (No opening) Comparative Present Present Present PresentX 85 13 Example 7 (No (No opening) opening) Comparative — PresentPresent Present X 87 12.6 Example 8 (No opening)

Examples 1 to 8

[0103] In Examples 1 to 8, IC cards were individually produced using anIC module having the structure shown in FIG. 2 in which the reinforcingsheet 16 was solely provided on the IC mounted surface. In the IC cardin each Example, an IC chip 14 having a 4 mm×4 mm form as a plane figurewas provided, and a circular reinforcing sheet 16 having a diameter of 7mm was disposed over the IC chip 14 so that their centers were alignedwith one another. Further, in the IC card in each of Examples 1 to 8,reinforcing film patterns 13, 13′ having the forms described below wereindividually provided.

Example 1

[0104] In the IC card in Example 1, there was used an IC module shown inthe plan view of FIG. 10 (as viewed from the top of the reinforcingsheet 16; this applies to the subsequent figures) in which thereinforcing film pattern 13 was solely disposed on the IC mountedsurface. The reinforcing film pattern 13 was formed into a square formhaving one side corresponding to a length shorter than the diameter ofthe reinforcing sheet 16 by 0.5 mm, namely, 6.5 mm×6.5 mm square outerperiphery form. In addition, in the reinforcing film pattern 13, anopening 13 a having a square form having one side corresponding to alength longer than the one side of the square IC chip 14 by 0.3 mm,namely, opening 13 a having a 4.3 mm×4.3 mm square form was formed. Theouter sides of the reinforcing film pattern 13 were respectivelyparallel to the corresponding sides of the opening 13 a. Further, thereinforcing film pattern 13 was obtained by forming a pattern in thesame conductive film as that used for the circuit pattern 12, andtherefore a bypass pattern 13 b was formed in the reinforcing filmpattern 13 at a position in which the circuit pattern 12 connected tothe IC chip 14 was formed so that the reinforcing film pattern 13 wassurely insulated from the circuit pattern 12. The bypass pattern 13 bhad a width larger than that of the circuit pattern 12 by 0.3 mm.

[0105] The reinforcing film pattern 13 having the above-described form,the IC chip 14, and the reinforcing sheet 16 were arranged so that theIC chip 14 was non-contact mounted in the opening 13 a of thereinforcing film pattern 13 and their centers were aligned with oneanother. Thus, the four corners of the reinforcing film pattern 13 are“projected” from the reinforcing sheet 16 as viewed from the top of thereinforcing sheet 16.

Example 2

[0106] In the IC card in Example 2, there was used an IC module shown inFIG. 11 in which the reinforcing film patterns 13, 13′ were respectivelydisposed on the IC mounted surface and the non-mounted surface. Theforms and configurations of the reinforcing pattern 13 on the IC chip 14mounted surface, and the reinforcing sheet 16 are the same as those inExample 1. The reinforcing pattern 13′ on the non-mounted surface hadthe same outer periphery form as that of the reinforcing film pattern 13on the mounted surface and had an opening 13 a′. No bypass pattern wasformed in the reinforcing film pattern 13′ at a position in which thecircuit pattern 12 was formed and a merely square opening 13 a′ wasformed in the center of the square pattern in the same direction.

[0107] The reinforcing film pattern 13 having the above-described form,the IC chip 14, the reinforcing sheet 16, and the reinforcing filmpattern 13′ were arranged so that the IC chip 14 was non-contact mountedin the reinforcing film pattern 13 and the reinforcing film pattern 13and the reinforcing film pattern 13′ were disposed in the same directionand their centers were aligned with one another. In the figure, thereinforcing pattern 13′ was shown to shift for explanation. In thisconfiguration, the four corners of the reinforcing film patterns 13, 13′are “projected” from the reinforcing sheet 16 as viewed from the top ofthe reinforcing sheet 16. Further, part of the circuit pattern 12connected to the IC chip 14 was overlapped on the reinforcing filmpattern 13′ on the non-mounted surface.

Example 3

[0108] In the IC card in Example 3, there was used an IC module shown inFIG. 12 in which the reinforcing film pattern 13′ was solely disposed onthe IC chip 14 non-mounted surface. The configuration of the IC chip 14,the reinforcing sheet 16, and the reinforcing film pattern 13′ is thesame as that in Example 2.

Example 4

[0109] In the IC card in Example 4, there was used an IC module shown inFIG. 13 in which the reinforcing film pattern 13 was solely disposed onthe IC mounted surface. In Example 4, the outer periphery form of thereinforcing film pattern 13 was an enlarged version of the one inExample 1 described with reference to FIG. 10 and other structure is thesame as that in Example 2. Specifically, the reinforcing film pattern 13was formed into a rectangle form having one side corresponding to alength longer than the diameter of the reinforcing sheet 16 by 2 mm,namely, 9 mm×9 mm rectangle form. Thus, whole of the outer periphery ofthe reinforcing film pattern 13 is “projected” from the reinforcingsheet 16 as viewed from the top of the reinforcing sheet 16.

Example 5

[0110] In the IC card in Example 5, there was used an IC module shown inFIG. 14 in which the reinforcing film patterns 13, 13′ were respectivelydisposed on the IC mounted surface and the non-mounted surface. InExample 5, the outer periphery forms of the reinforcing film patterns13, 13′ were an enlarged version of the corresponding ones in Example 2described with reference to FIG. 11 and other structure is the same asthat in Example 2. That is, the outer periphery forms of the reinforcingfilm patterns 13, 13′ are the same as that of the reinforcing filmpattern 13 in Example 4.

Example 6

[0111] In the IC card in Example 6, there was used an IC module shown inFIG. 15 in which the reinforcing film pattern 13′ was solely disposed onthe IC chip 14 non-mounted surface. The configuration of the IC chip 14,the reinforcing sheet 16, and the reinforcing film pattern 13′ is thesame as that in Example 5.

Example 7

[0112] In the IC card in Example 7, there was used an IC module shown inFIG. 16 in which the reinforcing film patterns 13, 13′ were respectivelydisposed on both of the IC mounted surface and the non-mounted surface.In Example 7, a bypass pattern 13 b′ was provided in the reinforcingfilm pattern 13′ in Example 2 described with reference to FIG. 11 at aposition in which the circuit pattern 12 was formed and other structureis the same as that in Example 2. Therefore, the circuit pattern 12connected to the IC chip 14 was not overlapped on the reinforcing filmpattern 13′ on the non-mounted surface. The bypass pattern 13 b had awidth larger than that of the circuit pattern 12 by 0.3 mm.

Example 8

[0113] In the IC card in Example 8, there was used an IC module shown inFIG. 17 in which the reinforcing film pattern 13′ was solely disposed onthe IC chip 14 non-mounted surface. The configuration of the IC chip 14,the reinforcing sheet 16, and the reinforcing film pattern 13′ is thesame as that in Example 7.

Examples 9 to 16

[0114] In Examples 9 to 16, IC cards were individually produced using anIC module having the structure shown in FIG. 8 in which the reinforcingsheets 16, 16′ were respectively provided on the IC mounted surface andthe back surface. The different structures in Examples 9 to 16 from thecorresponding ones in Examples 1 to 9 are that the reinforcing sheet 16′was provided also on the non-mounted surface, and other structures arethe same. Specifically, in the IC card in each Example, the IC chip 14and the reinforcing sheet 16 were arranged in the same manner as inExamples 1 to 8, and further the reinforcing sheet 16′ having the sameform as that of the reinforcing sheet 16 was disposed so that its centerwas aligned with the center of the reinforcing sheet 16. Further, in theIC card in each of Examples 9 to 16, the reinforcing film patterns 13,13′ having the forms in the corresponding Examples 1 to 8 were provided.The correspondences between the Examples and the figures for referenceare shown below.

[0115] Example 9 . . . Example 1 (FIG. 10)

[0116] Example 10 . . . Example 2 (FIG. 11)

[0117] Example 11 . . . Example 3 (FIG. 12)

[0118] Example 12 . . . Example 4 (FIG. 13)

[0119] Example 13 . . . Example 5 (FIG. 14)

[0120] Example 14 . . . Example 6 (FIG. 15)

[0121] Example 15 . . . Example 7 (FIG. 16)

[0122] Example 16 . . . Example 8 (FIG. 17)

Example 17

[0123] In Example 17, there was produced the same IC card as the IC cardusing an IC module having the structure shown in FIG. 2 in which thereinforcing sheet 16 was solely provided on the IC mounted surface,except that a reinforcing film pattern 13′ having a larger area wasdisposed only on the IC non-mounted surface so that the reinforcing filmpattern 13′ was overlapped on an about ⅓ portion of the circuit pattern12 on the IC mounted surface as shown in FIG. 18. The size of thereinforcing film pattern 13′ was about ⅓ of that of the insulatingsubstrate 11.

Examples 18 and 19

[0124] In these Examples, there were individually produced the same ICcards as the IC cards in Examples 13 and 14 described with reference toFIGS. 14 and 15, except that an IC module in which the reinforcing filmpattern 13′ on the non-mounted surface was divided into a plurality ofportions was used. In these Examples, as shown in FIG. 19 and FIG. 20,the reinforcing film pattern 13′ on the non-mounted surface was dividedinto two portions, i.e., a portion to be overlapped on the In-part ofthe circuit pattern 12 connected to the IC chip 14 and a portion to beoverlapped on the Out-part of the circuit pattern 12. Thecorrespondences between Examples 18 and 19 and Examples 13 and 14 andthe figures for reference are shown below.

[0125] Example 18 . . . Example 13 (FIG. 19)

[0126] Example 19 . . . Example 14 (FIG. 20)

Comparative Examples 1 and 2

[0127] In Comparative Examples 1 and 2, IC cards having conventionalstructures were individually produced using IC modules in which thereinforcing film patterns 13, 13′ were not provided. Specifically, inComparative Example 1, an IC card in which the reinforcing sheet 16 wassolely provided on the IC mounted surface was produced, and, inComparative Example 2, an IC card in which the reinforcing sheets 16,16′ were respectively provided on the IC mounted surface and thenon-mounted surface was produced.

Comparative Examples 3 to 5

[0128] In Comparative Examples 3 to 5, IC cards were individuallyproduced using an IC module having the structure shown in FIG. 2 inwhich the reinforcing sheet 16 was solely provided on the IC mountedsurface. It is noted that, in the IC card in each Comparative Example,reinforcing film patterns 103, 103′ having no opening in the IC chipmounted portion were provided as shown in FIGS. 21 to 23. Further, thereinforcing film patterns 103, 103′ in Comparative Examples 3 to 5 areprovided in the outer periphery forms and configurations respectivelycorresponding to those in Examples 1 to 3. The correspondences betweenExamples 1 to 3 and Comparative Examples 3 to 5 and the figures forreference are shown below.

[0129] Comparative Example 3 . . . Example 1 (FIG. 21)

[0130] Comparative Example 4 . . . Example 2 (FIG. 22)

[0131] Comparative Example 5 . . . Example 3 (FIG. 23)

Comparative Examples 6 to 8

[0132] Comparative Examples 6 to 8 are examples of the IC card havingthe structure shown in FIG. 8 in which the reinforcing sheets 16, 16′were respectively provided on the IC mounted surface and the non-mountedsurface, using an IC module in which the reinforcing film patterns 103,103′ having no opening in the IC chip mounted portion were provided. Thereinforcing film patterns 103, 103′ in each of Comparative Examples 6 to8 are provided in the outer periphery forms and configurationsrespectively corresponding to those in Examples 1 to 3. Thecorrespondences between Examples 1 to 3 and Comparative Examples 6 to 8and the figures for reference are shown below.

[0133] Comparative Example 6 . . . Example 1 (FIG. 21)

[0134] Comparative Example 7 . . . Example 2 (FIG. 22)

[0135] Comparative Example 8 . . . Example 3 (FIG. 23)

[0136] In the IC card in each of Comparative Examples 3, 4, 6, and 8 inwhich the reinforcing film pattern 103 was provided on the IC mountedsurface, the reinforcing pattern 103 was provided so that it integratedwith the supporting pattern 18 for supporting the IC chip 14 (see FIG.2).

[0137] Next, the procedure for producing the IC cards in the aboveExamples and Comparative Examples is described below.

[0138] {circle over (1)} First, an IC module was produced as follows.

[0139] An aluminum foil (20 μm) was applied to the IC mounted surface ofan insulating substrate 11 comprised of polyethylene terephthalate(thickness=50 μm) to form a resist pattern in the aluminum foil. Then,the aluminum foil was etched using the resist pattern as a mask to forma circuit pattern 12 comprised of aluminum on the polyethyleneterephthalate and a reinforcing film pattern 13 and a supporting pattern18 for the IC chip 14 which were not in contact with the circuit pattern12. In the Comparative Examples, a reinforcing film pattern 103 wasformed. Further, when a reinforcing film pattern 13′ was formed on an ICnon-mounted surface, the same procedure was conducted to form thereinforcing film pattern 13′ comprised of aluminum (reinforcing filmpattern 103′) having an individual form. Thus, an antenna module(flexible printed board) having the circuit pattern 12 formed on theinsulating substrate 11 was prepared.

[0140] An IC chip (length: 4 mm×width: 4 mm×thickness: 180 μm) 14 wasmounted by face down bonding on the antenna module through ananisotropic conductive adhesive layer 17, and the IC chip 14 was sealedby an epoxy sealing resin 15 and a reinforcing sheet 16 was placed abovethe resin. Then, the sealing resin 15 was cured at 100° C. On the otherhand, when a reinforcing sheet 16′ was provided on the IC non-mountedsurface, the reinforcing sheet 16′ was provided on the non-mountedsurface of the insulating substrate 11 through a sealing resin 15′, andthen the sealing resin 15′ was cured at 100° C. Thus, an IC module 1 wasproduced. As the reinforcing sheets 16, 16′, a sheet obtained by shapingSUS304H specified in JIS so as to have a thickness of 50 μm was used.

[0141] {circle over (2)} Subsequently, a card substrate was produced asfollows.

[0142] Front and back end thermoplastic sheets (thickness=280 μm) 21,21′ comprised of PET-G (copolymer of terephthalic acid,cyclohexanedimethanol, and ethylene glycol) having white filler(titanium oxide) mixed thereinto were prepared. The IC module 1previously prepared was disposed between the thermoplastic sheets 21,21′, and the four corners of the thermoplastic sheets 21, 21′ weremelted by means of an ultrasonic bonding machine to temporarily fix themtogether. Then, oriented polypropylene (OPP) film sheets were placed onboth surfaces of the sheets temporarily fixed, and they were togetherdisposed between stainless steel mirror plates (thickness=3 mm) andmelted by means of a hot-melt press under conditions such that thetemperature was 170° C. and the pressing pressure was 15kg/cm2 , andthen solidified by cooling and the OPP sheets were peeled off to obtaina card substrate 2 having the IC module 1 sealed therein.

[0143] {circle over (3)} Further, printed sheets were produced asfollows.

[0144] Patterns for front and back surfaces were individually printed onsheets comprised of polyethylene terephthalate (thickness=100 μm) bysilk printing/offset printing, and an adhesive coating composition shownbelow was applied to the back surface of each of the resultant printedsheets by a gravure printing method so that the thickness of thecomposition applied became 3 μm, and dried at a drying temperature of100° C. Thus, a printed sheet for front surface and a printed sheet forback surface were produced. <Formulation of adhesive coatingcomposition> Polyester resin 40 Parts by weight Toluene 50 Parts byweight Methyl ethyl ketone 50 Parts by weight

[0145] {circle over (4)} In addition, a reversible recording sheet wasprepared.

[0146] As a reversible recording sheet, a lueco thermal recording sheet(manufactured and sold by MITSUBISHI PAPER MILLS LIMITED; product name:TRF33) was prepared. The thermal recording sheet has a structure suchthat a base material comprised of polyethylene terephthalate has athickness of 25 μm, a recording layer provided on the base material hasa thickness of 7 μm, and a protecting layer for the recording layer hasa thickness of 3 μm.

[0147] {circle over (5)} The individual members were produced asdescribed above, and then a card was formed using them as follows.

[0148] First, the printed sheet for front surface obtained in {circleover (3)} was disposed on the card substrate 2 produced in {circle over(2)} on the thermoplastic sheet 21 side (IC mounted surface side), andthe printed sheet for back surface obtained in {circle over (2)} wasdisposed on the thermoplastic sheet 21′ side (non-mounted surface side).Each printed sheet was disposed so that the printed surface was outside.Then, the reversible recording sheet obtained in {circle over (2)} wasdisposed on the printed sheet for front surface so that the protectinglayer was outside. The resultant laminate was temporarily fixed again bymeans of an ultrasonic bonding machine. Oriented polypropylene filmsheets were placed on both sides of the sheets temporarily fixed, andthey were together disposed between stainless steel mirror plates(thickness=3 mm), and melted by means of a vacuum hot-melt press underconditions such that the temperature was 120° C. and the pressingpressure was 15 kg/cm², and then solidified by cooling, followed bypunching out into a card form, thus producing IC cards in the Examplesand Comparative Examples, in which the reversible recording layer 3 wasprovided on the card substrate 2.

[0149] {circle over (5)} Evaluation

[0150] Using the thus produced IC cards in Examples 1 to 19 andComparative Examples 1 to 8 as samples for evaluation, the printingproperties for the reversible recording layer 3, the communicationcharacteristics, and the IC strength were evaluated as follows. Theresults of the evaluations are shown in Table 1 above.

[0151] Printing properties

[0152] With respect to the reversible recording layer 3, printing wasconducted using a thermal printer (KUZ), manufactured and sold by KyushuMatsushita Electric Co., Ltd., at energy applied to a thermal head of0.55 mJ/dot. In the portion of the reversible recording layer 3 on theIC chip mounted portion, when print missing occurred, the printingproperties were rated X; when slight touching occurred on the printedportion, the printing properties were rated Δ; and, when no printmissing occurred, the printing properties were rated ∘.

[0153] Communication Characteristics

[0154] Using a communication distance between a reader/writer and an ICcard as a factor, the IC card operation was examined using areader/writer (communication device), manufactured and sold by SonyCorporation, to measure a maximum communication distance, and thedistance measured was taken as communication characteristics.

[0155] IC Strength

[0156] A load (static load strength) applied until the IC chip wasbroken on the IC chip mounted portion was evaluated. The position towhich a load was applied was the center of the IC chip mounted portion,the tip of a gage head had a form of sphere having a radius of 0.2 mm,and the loading speed was 0.5 mm/min, and the breakage of the IC chipwas evaluated in terms of a point in time when the communication wasimpossible; In the examination of the IC operation, a reader/writer(communication device), manufactured and sold by Sony Corporation, wasused.

[0157] As a result of the above evaluations, it has been confirmed that,in the IC card in each of Examples 1 to 19, i.e., the IC card having thereinforcing film patterns 13, 13′ having openings in which the IC chip14 is mounted, the printing properties for the reversible recordinglayer 3 are rated Δ or ∘ and kept in good condition. Especially inExamples 2, 5, 7, 10, 13, and 15 in which the reinforcing film patterns13, 13′ were respectively provided on both of the IC mounted surface andthe non-mounted surface, and in Examples 4, 6, 12, and 14 in which thereinforcing film pattern 13 or 13′ having a size sufficient to be coverthe reinforcing sheets 16, 16′ was provided on one surface, it has beenconfirmed that very good printing properties (∘) such that no slighttouching occurred on the printed portion can be secured.

[0158] By contrast, in the conventional IC card in each of ComparativeExamples 1 and 2 in which no reinforcing film pattern was provided likethe conventional way, and in the IC card each of Comparative Examples 3to 8 in which the reinforcing film patterns 103, 103′ having no openingin which the IC chip is mounted were provided, print missing occurred(printing properties: X) and the printing properties could not be keptin good condition.

[0159] Further, among Examples 1 to 19, in Examples 1, 4, 9, and 12 inwhich no reinforcing film pattern was provided on the non-mountedsurface and there was no portion of the reinforcing film patternoverlapped on the circuit pattern 12, and in Examples 7, 8, 15, and 16in which the reinforcing film pattern 13′ was provided on thenon-mounted surface, but there was no portion of the reinforcing filmpattern 13′ overlapped on the circuit pattern 12, it has been confirmedthat communication characteristics equivalent to those obtained inComparative Examples 1 and 2 as conventional technique examples can besecured. In addition to the above results, in Example 17 in which theportion of the reinforcing film pattern 13′ on the non-mounted surfaceoverlapped on the circuit pattern 12 was larger, communicationcharacteristics cannot be obtained. From these results, it has beenconfirmed that, when the reinforcing film pattern 13′ on the non-mountedsurface is comprised of a conductive material, by reducing the portionof the reinforcing film pattern 13′ overlapped on the circuit pattern12, the communication characteristics can be kept in better condition.

[0160] In addition, among Examples 1 to 19, in Examples 18 and 19 inwhich the reinforcing film pattern 13′ on the non-mounted surface wasdivided per portion to be overlapped on the circuit pattern 12, it hasbeen confirmed that communication characteristics equivalent to thoseobtained in Comparative Examples 1 and 2 as conventional techniqueexamples can be secured. From this result, it has been confirmed that,when the reinforcing film pattern 13′ on the non-mounted surface iscomprised of a conductive material, by dividing the reinforcing filmpattern 13′ per portion to be overlapped on the circuit pattern 12, thecommunication characteristics can be kept in better condition.

[0161] Further, the IC strength in Examples 1 to 8, in which thereinforcing sheet 16 was solely provided on the mounted surface, is at alevel equivalent to that of the IC strength (static load strength) inComparative Example 1, in which the reinforcing sheet was solelyprovided similarly on the mounted surface, and thus, it has beenconfirmed that the IC strength is not lowered due to the reinforcingfilm patterns 13, 13′ provided and the protection of the IC chip 14 bythe reinforcing sheet 16 is kept.

[0162] Further, the IC strength in Examples 9 to 16, in which thereinforcing sheets 16, 16′ were respectively provided on the mountedsurface and the non-mounted surface, is at a level equivalent to that ofthe IC strength (static load strength) in Comparative Example 2, inwhich the reinforcing sheets were similarly provided on the respectivesurfaces, and thus, it has been confirmed that the IC strength is notlowered due to the reinforcing film patterns 13, 13′ provided and theprotection of the IC chip 14 by the reinforcing sheets 16, 16′ is kept.

[0163] As described above, in the IC card of the present invention, byproviding a reinforcing film pattern on both of the insulating substratefor the IC module, deformation of the reinforcing sheet provided on theIC chip can be suppressed and flatness of the surface including portionsaround the IC chip mounted portion can be secured. Therefore, in the ICcard in which the IC chip is protected by the reinforcing sheet toimprove the reliability, printing properties for the reversible displaylayer provided on the surface of the substrate can be improved.

1. An IC card comprising: an IC module which comprises an IC chipmounted on an insulating substrate, and a reinforcing sheet providedover said IC chip through a sealing resin for sealing said IC chip; acard substrate comprised of a resin for sealing said IC module; and areversible display layer provided on at least one surface of said cardsubstrate, said IC card being characterized in that a reinforcing filmpattern having an opening which exposes an IC chip mounted portion isprovided on at least one of an IC chip mounted surface and a non-mountedsurface of said insulating substrate.
 2. The IC card according to claim1, characterized in that a periphery of said opening in said reinforcingfilm pattern is located on the IC chip side than on an outer peripheryof said reinforcing sheet.
 3. The IC card according to claim 1,characterized in that at least part of an outer periphery of saidreinforcing film pattern is located outside an outer periphery of saidreinforcing sheet.
 4. The IC card according to claim 1, characterized inthat said insulating substrate has a reinforcing sheet provided on saidnon-mounted surface through an adhesive at a position corresponding tosaid IC chip mounted portion.
 5. The IC card according to claim 1,characterized in that said insulating substrate has a circuit patternformed on said mounted surface, wherein said reinforcing film patternprovided on said mounted surface is comprised of the same material asthat for said circuit pattern.
 6. The IC card according to claim 1,characterized in that said insulating substrate has a circuit patternformed on said IC chip mounted surface, wherein said reinforcing filmpattern provided on said non-mounted surface of said insulatingsubstrate is comprised of a conductive material and has a form such thatno portion is overlapped on said circuit pattern.
 7. The IC cardaccording to claim 1, characterized in that said insulating substratehas a circuit pattern formed on said IC chip mounted surface, whereinsaid reinforcing film pattern provided on said non-mounted surface ofsaid insulating substrate is comprised of a conductive material anddivided into a plurality of portions per portion to be overlapped onsaid circuit pattern.
 8. The IC card according to claim 1, characterizedin that said reinforcing film pattern is comprised of an insulatingmaterial.